opentelemetry-java-instrumentation/instrumentation-docs

Doc Generator

Runs analysis on instrumentation modules in order to generate documentation.

How to use

Run the analysis to update the instrumentation-list.yaml:

./gradlew :instrumentation-docs:runAnalysis

Instrumentation Hierarchy

An "InstrumentationModule" represents a module that that targets specific code in a framework/library/technology. Each module will have a name, a namespace, and a group.

Using these structures as examples:

├── instrumentation
│   ├── clickhouse-client-05
│   ├── jaxrs
│   │   ├── jaxrs-1.0
│   │   ├── jaxrs-2.0
│   ├── spring
│   │   ├── spring-cloud-gateway
│   │   │   ├── spring-cloud-gateway-2.0
│   │   │   ├── spring-cloud-gateway-2.2
│   │   │   └── spring-cloud-gateway-common

Results in the following:

• Name - the full name of the instrumentation module
  • clickhouse-client-05, jaxrs-1.0, spring-cloud-gateway-2.0
• Namespace - direct parent. if none, use name and strip version
  • clickhouse-client, jaxrs, spring-cloud-gateway
• Group - top most parent
  • clickhouse-client, jaxrs, spring

This information is also referenced in InstrumentationModule code for each module:

public class SpringWebInstrumentationModule extends InstrumentationModule
    implements ExperimentalInstrumentationModule {
  public SpringWebInstrumentationModule() {
    super("spring-web", "spring-web-3.1");
  }

Instrumentation metadata

• classification
  • library - Instrumentation that targets a library
  • internal - Instrumentation that is used internally by the OpenTelemetry Java Agent
  • custom - Utilities that are used to create custom instrumentation
• name
  • Identifier for instrumentation module, used to enable/disable
  • Configured in InstrumentationModule code for each module
• source_path
  • Path to the source code of the instrumentation module
• minimum_java_version
  • Minimum Java version required by the instrumentation module. If not specified, it is assumed to be Java 8
• description
  • Short description of what the instrumentation does
• target_versions
  • List of supported versions by the module, broken down by library or javaagent support
• scope
  • Name: The scope name of the instrumentation, io.opentelemetry.{instrumentation name}
• configurations settings
  • List of settings that are available for the instrumentation module
  • Each setting has a name, description, type, and default value

Methodology

metadata.yaml file

Within each instrumentation source directory, a metadata.yaml file can be created to provide additional information about the instrumentation module.

As of now, the following fields are supported, all of which are optional:

description: "Instruments..."   # Description of the instrumentation module
disabled_by_default: true       # Defaults to `false`
classification: internal        # instrumentation classification: library | internal | custom
configurations:
  - name: otel.instrumentation.common.db-statement-sanitizer.enabled
    description: Enables statement sanitization for database queries.
    type: boolean               # boolean | string | list | map
    default: true

Gradle File Derived Information

We parse gradle files in order to determine several pieces of metadata:

• Javaagent versions are determined by the muzzle plugin configurations
• Library versions are determined by the library dependency versions
  • when available, latestDepTestLibrary is used to determine the latest supported version
• Minimum Java version is determined by the otelJava configurations

Scope

For now, the scope name is the only value that is implemented in our instrumentations. The scope name is determined by the instrumentation module name: io.opentelemetry.{instrumentation name}

We will implement gatherers for the schemaUrl and scope attributes when instrumentations start implementing them.